This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Proteins are the biological machinery of the cell, and if this machinery is altered, e.g. via modification of a component, addition or absence of a protein, this changes cell behaviour. Such changes are the root of many pathologies, including the pregnancy condition pre-eclampsia. In this disease, poor placental blood supply induces release of factors into the mothers'bloodstream. These factors induce blood vessel damage, causing blood vessels to become leaky. Leakiness leads to fluid escape from vessels, and thus the pre-eclampsia symptoms, e.g. elevated blood pressure and urine protein, and swelling of the hands and face. Release of placental factors occurs before any observable symptoms, and no screening methods exists. Identification of proteins from blood plasma or urine is a vital step towards screening tests for proteins within prenatal care regimes. Methods to identify proteins within biological samples using analytical chemistry are termed proteomics. A common step in proteomic workflows is protein digestion to give smaller peptides, using specific protease enzymes. This converts a mixture of thousands of proteins into a mixture of hundreds of thousands of shorter peptides. Electron transfer dissociation works best with longer polypeptides. This study examines proteolysis conditions, different enzymes and chemical cleavage and native peptides. We use urine and blood from women with pre-eclampsia to identify proteins whose abundance is altered between uncomplicated pregnancy and samples taken during development of pre-eclampsia.. This will enable increased understanding of pre-eclampsia's causes and establishment of a panel of markers for testing of samples during pregnancy. Eventually, this will allow identification, streaming and management of women who would otherwise suffer pre-eclampsia.